An example of a known radial magnetic bearing is disclosed in document U.S. Pat. No. 4,720,649 A. A portion (quadrant) of such a kind of known radial magnetic bearing is illustrated in FIG. 9. Such a radial magnetic bearing comprises a stator 2 surrounding a rotor 1. The rotor 1 comprises a central shaft 10 having a stack of high quality magnetic laminations 11 around its periphery, the laminations being made of a material such as stainless ferritic iron or silicon iron. The stator 2 comprises a magnetic circuit having a peripheral portion 23 which interconnects a plurality of pairs of poles 21 which project radially inwardly towards the rotor 1. Electromagnetic windings 22 are disposed around the various poles 21. The complete stator comprises at least four pairs of poles 21 disposed along two mutually perpendicular axes, which makes it possible to hold the rotor 1 in a predetermined radial position. The stator 2 is enclosed in a casing 24. The poles 21 and the peripheral portion 23 of the stator 2 are made from a stack of disc-like plates or washers.
The manufacturing process implies the assembly of steel sheet elements such as the stack of disc-like plates 21, 23 which constitute so-called horn bearings and may have a large diameter. Furthermore the implementation of coils 22 implies a great number of interconnections, which is not cost effective. Consequently the manufacturing and assembly time is not in accordance with serial production. Moreover, the process of mounting coils 22 around the poles 21 requires an adaptation of the shape of the slots and horns laminations or disc-like plates, but this adaptation leads to a drop in the overall performance of the radial load capacity of the magnetic bearing.